I am the onwer of OLED936, love it. I am not gamer and I watch TV mainly for TV programs or movie. picture, sound and ambilight together are really a fantastic combination! I do see the TV can support 4k120hz when connecting to Xbox Series X. Your video shows the Xbox TV status report page is different from mine. I guess you may connect Xbox to HDMI3 or 4 of TV. My understanding is OLED936 and 986 is the same in video specification and only HDMI1 and 2 support 4k120hz but HDMI3 and 4 not. Hope it can be reconfirmed by you to let other viewers get updated result. attached my TV screen shot when connecting Xbox.
Neither the OLED+936 or 986 support full resolution 4K/120 due to the dual MediaTek chip approach used by the OLED+ TVs. This has been confirmed by Philips in a recent thread on AVForums. You are correct that there are only two full-fat 48Gbps HDMI inputs, this is well known and used in the video. Thanks for your comment.